(1) Field of the Invention
The invention relates to a method for data collection, and more specifically to a method for data collection during manufacturing processes that will result in relief of load on the host and on the manufacturing equipment.
(2) Description of the Prior Art
Implementing advanced process control (APC) has imposed a heavy load on both the host system and the equipment controller. In APC, a model is built to analyze time series data in real-time and to generate an alert when a fault is detected. The reliability of the control model depends on the accuracy and the consistency of the data collected.
Time series data can be collected in two ways:
1) Trace data—A method of data collection in which equipment is set up to send a pre-defined set of data at a preset interval. The minimum trace interval is one second using the trace data collection method.
2) Polling—A method of data collection in which the host is set up to request a pre-defined set of data at a preset interval. Using this method, a sub-second interval (0.5 second) can be achieved.
Both of the above-mentioned data collection methods impose loading on either the equipment (trace data) or the host (polling) when time series data collection is enabled. The data collection job takes up processing resources of either the equipment or the host.
U.S. Pat. No. 6,070,196 to Mullen, Jr. discloses a protocol converter controller having distributed architecture. U.S. Pat. No. 6,532,434, to West describes a modular data sensing and logging system. A control module interfaces between a host computer and data acquisition modules. International Patent Publication WO 01/52320 A2 to Coss, Jr. et al describes an Advanced Process Control (APC) system that includes a method for an operator to request trace data reports from a fabrication tool via a report generator interface. U.S. Patent Application 2003/0083754 A1 to Tripathi et al shows a device and method for communicating data in a process control system. U.S. Pat. No. 6,208,904 to Mullen, Jr. teaches a general purpose data communications protocol converter. U.S. Pat. No. 6,708,074 to Chi et al discloses a generic interface builder used to add tools or systems to a centralized manufacturing system. U.S. Pat. No. 6,721,618 to Baek et al teaches a system and method for automatically generating SECS messages for a process control system. U.S. Pat. No. 6,556,881 to Miller shows an apparatus and a process for integrating real-time fault detection into an APC framework. U.S. Patent Application 2004/0040001 to Miller et al teaches a method to predict device electrical parameters during fabrication. U.S. Pat. No. 6,535,783 to Miller et al teaches processing of sensor data from a process tool in an APC system. U.S. Pat. No. 6,725,402 to Coss, Jr. et al and U.S. Pat. No. 6,546,508 to Sonderman et al disclose a method and apparatus for fault detection of a processing tool in an APC system.